Vandalism of coin-operated public-pay telephones is one of the biggest problems facing public and private telephone companies. Pay phones are exposed day and night to professional and amateur criminals who find the significant sums of money collected therein on a continuous basis, a serious temptation. The exposed and isolated nature of pay phone installations renders the vandalism acts relatively safe for the criminal.
A coin pay telephone includes a coin return assembly or bucket to which normally a would-be caller's money is returned when his or her call is not completed, as when the called number is busy. Vandals have discovered that all coins deposited in a telephone, for both completed and not completed calls, can be sent to the coin return bucket via the relay controlling the coin switch which normally directs inserted coins to either the coin return bucket or to the telephone coin box. They achieve this by grounding the coin switch relay to neutralize it, and leaving the ground in place.
The coin switch in its closed position holds up the coins deposited by the telephone user; when moved to one open position, as when a call is completed, it directs the just-deposited coins being held in a chute, to the coin box; however, when moved to the other open position, as when a call is not completed, it directs the just-deposited coins to the coin return bucket for picking up by the would-be caller.
A coin pay telephone also includes a key pad on the back of he dial housing having twelve push buttons extending through the front of the telephone upper housing for depressing according to the number to be called. The key pad mounts on its rear, numbered terminals for effecting electrical connections according to the push buttons pushed. The wiring between each of the key pad terminals numbered 1 and 12 and the coin switch relay, is such that when either of them is placed at system electrical ground, the relay is grounded and placed in a neutralized condition and the coin switch goes to closed position to which it is biased and remains there to hold up all coins inserted for both completed and not completed calls. Inserted coins cannot thereafter be passed on to the telephone coin box nor to the coin return bucket, though telephone calls can be both attempted and completed. Telephone users completing their calls will not notice the difference.
One way vandals ground the coin switch relay is by inserting a bare wire through the MEDECO lock (upper housing lock located on the left side of the upper housing and opposite the key pad terminal) which has a out slot through its cylinder, and touching one of key pad terminals numbered 1 or 12. This applies the system ground on the housing to the touched terminal which neutralizes the relay and allows the coin switch to assume the closed position in which it holds up all subsequently deposited coins, those for both completed and not completed calls. Pay telephone users are thus deprived immediately of their monies inserted for unsuccesssful calls; the telephone company eventually does not collect its monies for services rendered in completing calls and that it normally picks up on a regular schedule.
Before the regular-schedule pick-up time, the vandal returns to retrieve the coins deposited in the meantime. He first removes the ground to one of the key pad terminals numbered "1" or "12". He then goes "off-hook", and immediately hangs up. The coin operated telephone now works as it should, and "return current" comes out to the coin telephone from the "central office". The "return current" operates the coin switch relay to return it to the other open position in which it allows all coins to move under the influence of gravity to the coin return bucket. All of the coins, for both incompleted and completed calls, which were deposited during the period the coin switch relay was grounded, will now be available to the returning vandal who rifles the coin return bucket for its contents. The ground may now be reapplied, or it may be left off until after the next telephone company collection visit to allow the collection of a few coins in the telephone coin box and not alert the company to the fraud being practiced.
Thus both the unsuccessful callers and the phone company are defrauded of their rightful monies. In addition, the phone company is subjected to the ill will of unsuccessful callers who don't recover their coins.